578 research outputs found
The impact of urban concentration on countries’ competitiveness and entrepreneurial performance
This paper aims to elaborate the role of Jacobs-type of agglomeration effects on countries’
competitiveness and entrepreneurial performance. Our research allows for a better
understanding of the relationship that exists between a country’s urban system,
characterized by spatial agglomeration (concentration) or deglomeration (deconcentration)
processes, and its competitiveness and entrepreneurial performance.
Urbanization economies refer to considerable cost savings generated through the
locating together of people, firms and organizations across different industries. It has
recently become an axiom that the better performance of global cities (as they are important
nodes of innovation and creativity) is derived from agglomeration effects. This general
assumption follows that the more concentrated an urban system of a country, the more
competitive and better its entrepreneurial performance. Even though this notion has gained
quick and ardent acceptance from practitioners, the related literature shows contradictory
results;this has induced a heated debate in academic circles, because it has raised serious
doubts about the “bigger is better” theory. We hope to contribute to this debate with our
detailed analysis.
To understand the impact of urban concentration, we selected 70 countries and
calculated the so-called ROXY Index measuring the degree of agglomeration or
deglomeration in their urban systems. To exemplify country-level competitiveness, we
applied the Global Competitiveness Index (GCI) while the Global Entrepreneurship and
Development Index (GEDI) was used to demonstrate country level entrepreneurial
performance. Using these indexes correlation and cluster analysis were designed to obtain
understanding of the relationship between them.
Our analysis indicates that as urban concentration initially increases competitiveness,
entrepreneurial performance also increases, but at a decreasing rate. Both of them
eventually reaches a maximum, and then after a certain point decrease with further
concentration. Therefore, the curve for this relationship is non-linear and folds back. This
indicates that over- or under-concentration of the population within an urban system does
not necessarily result in a better outcome. However, we should consider that a high
concentration of population is only one important factor for competitiveness and
entrepreneurial performance while other effects may exis
Savanyú vulkáni üvegek ásványtan-geokémiai vizsgálata, petrológiai és vulkanológiai kiértékelése = Mineralogical and geochemical study of acid volcanic glasses, and its interpretation from petrological and volcanological point of view
Változatos lemeztektonikai környezetben kĂ©pzĹ‘dött obszidián minták fĹ‘- Ă©s nyomelemtartalmának összehasonlĂtĂł vizsgálata során megállapĂtottuk, hogy az eredetileg gránitokra kidolgozott diszkrimináciĂłs diagramok alkalmazhatĂłk a savanyĂş kiömlĂ©si kĹ‘zetek esetĂ©ben is. MegállapĂtottuk, hogy az Ăłceáni sziget bazaltok (OIB) Ă©s a szigetĂv mĂ©szalkáli bazaltok (IAB) chondritra normált spiderdiagramjainak nĂ©hány alapvetĹ‘ jellegzetessĂ©ge (pl. a relatĂv Nb-Ta minimum, ill. relatĂv Nb-Ta maximum) az obszidiánminták spiderdiagramjának patternjĂ©nĂ©l is felismerhetĹ‘. Vizsgáltuk a mikro-PIXE elemzĂ©sek megbĂzhatĂłságát Ă©s felhasználhatĂłságát, s bemutattuk, hogy az ezzel a mĂłdszerrel kĂ©szĂtett piroxĂ©nelemzĂ©si eredmĂ©nyek alkalmasak geotermometriai számĂtások elvĂ©gzĂ©sĂ©re. SavanyĂş vulkáni ĂĽvegek mállási folyamatát riolittuffa mintákon vizsgáltuk. A minták ásványos Ă©s fĹ‘elem-összetĂ©telĂ©nek valamint termoanalitikai paramĂ©tereinek (TG) összehasonlĂtása alapján megállapĂtottuk, hogy a mállási fok jellemzĂ©sĂ©re egyes TG paramĂ©terek a nemzetközi gyakorlatban elterjedt indexhez (CIA) hasonlĂł megbĂzhatĂłsággal rendelkezik. RĂ©szt vettĂĽnk egy olyan berendezĂ©s kifejlesztĂ©sĂ©ben, ami magas hĹ‘mĂ©rsĂ©kleten direkt mintavĂ©telt tesz lehetĹ‘vĂ© tömegspektrometriai vizsgálatokhoz. E berendezĂ©st vulkáni ĂĽvegek termális bomlási folyamatainak tanulmányozásánál is hasznosĂtani lehet. | Major and trace element spectra of obsidian samples from various tectonic settings were performed by LA-ICP-MSand PIGE techniques. The results suggest that discrimination diagrams for granites may be used for acidic volcanic rocks, too. We found that some characterisctic patterns of chondrite normalised spider diagram of OIB and IAB (such as relative Nb-Ta minimum and relative Nb-Ta maximum, respectively) can be observed in the case of obsidians, too. We demonstrate that analytical data yielded by micro-PIXE measurements can be applied even for geothermometric estimations. Weathering process of acidic volcanic glasses was studied on rhyolite tuff samples. Comparing mineralogical and major element composition as well as some thermoanalytical parameters of the samples it can be stated on the basis of some TG parameters weathering degree of rhyolite tuffs can be determined with a reliability that similar to that of the internationally accepted CIA index. We participated in construction of high temperature direct probe coupled to a quadrupole MS. This device can be also used for monitoring thermal decomposition of volcanic glasses
A Szentendrei-sziget zárt ártéri tölgyesei (Melico nutantis-Quercetum roboris KEVEY 2008)
Jelen tanulmány a Szentendrei-sziget zárt száraz tölgyeseinek társulási viszonyait muÂtatja be tĂz cönolĂłgiai felvĂ©tel alapján. A felmĂ©rt állományok az egyĂ©b alföldi tájak erdei közĂĽl a SzigetÂköz zárt ártĂ©ri tölgyeseivel (Melico nutantis-Quercetum roboris) mutatják a legközelebbi rokonságot. Az elemzĂ©si eredmĂ©nyek szerint ezen erdĹ‘kben az elmĂşlt 70 Ă©v alatt megnövekedett a termĂ©szetes gyoÂmok (W), a meghonosodott idegen fajok (I) Ă©s az agresszĂv tájidegen inváziĂłs fajok (AC) aránya.</jats:p
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